* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
+/* ====================================================================
+ * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
#include <stdio.h>
#include <time.h>
#include "bn_lcl.h"
#include <openssl/rand.h>
+/* NB: these functions have been "upgraded", the deprecated versions (which are
+ * compatibility wrappers using these functions) are in bn_depr.c.
+ * - Geoff
+ */
+
/* The quick sieve algorithm approach to weeding out primes is
* Philip Zimmermann's, as implemented in PGP. I have had a read of
* his comments and implemented my own version.
*/
#include "bn_prime.h"
-/* number of Miller-Rabin iterations for an error rate of less than 2^-80
- * for random 'b'-bit input, b >= 100 (taken from table 4.4 in the Handbook
- * of Applied Cryptography [Menezes, van Oorschot, Vanstone; CRC Press 1996];
- * original paper: Damgaard, Landrock, Pomerance: Average case error estimates
- * for the strong probable prime test. -- Math. Comp. 61 (1993) 177-194) */
-#define BN_prime_checks_size(b) ((b) >= 1300 ? 2 : \
- (b) >= 850 ? 3 : \
- (b) >= 650 ? 4 : \
- (b) >= 550 ? 5 : \
- (b) >= 450 ? 6 : \
- (b) >= 400 ? 7 : \
- (b) >= 350 ? 8 : \
- (b) >= 300 ? 9 : \
- (b) >= 250 ? 12 : \
- (b) >= 200 ? 15 : \
- (b) >= 150 ? 18 : \
- /* b >= 100 */ 27)
-
-static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx,BN_CTX *ctx2,
- BN_MONT_CTX *mont);
+static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
+ const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont);
static int probable_prime(BIGNUM *rnd, int bits);
-static int probable_prime_dh(BIGNUM *rnd, int bits,
- BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
static int probable_prime_dh_safe(BIGNUM *rnd, int bits,
- BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
+ const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
+
+static int prime_offsets[480] = {
+ 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89,
+ 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167,
+ 169, 173, 179, 181, 191, 193, 197, 199, 211, 221, 223, 227, 229, 233, 239,
+ 241, 247, 251, 257, 263, 269, 271, 277, 281, 283, 289, 293, 299, 307, 311,
+ 313, 317, 323, 331, 337, 347, 349, 353, 359, 361, 367, 373, 377, 379, 383,
+ 389, 391, 397, 401, 403, 409, 419, 421, 431, 433, 437, 439, 443, 449, 457,
+ 461, 463, 467, 479, 481, 487, 491, 493, 499, 503, 509, 521, 523, 527, 529,
+ 533, 541, 547, 551, 557, 559, 563, 569, 571, 577, 587, 589, 593, 599, 601,
+ 607, 611, 613, 617, 619, 629, 631, 641, 643, 647, 653, 659, 661, 667, 673,
+ 677, 683, 689, 691, 697, 701, 703, 709, 713, 719, 727, 731, 733, 739, 743,
+ 751, 757, 761, 767, 769, 773, 779, 787, 793, 797, 799, 809, 811, 817, 821,
+ 823, 827, 829, 839, 841, 851, 853, 857, 859, 863, 871, 877, 881, 883, 887,
+ 893, 899, 901, 907, 911, 919, 923, 929, 937, 941, 943, 947, 949, 953, 961,
+ 967, 971, 977, 983, 989, 991, 997, 1003, 1007, 1009, 1013, 1019, 1021, 1027,
+ 1031, 1033, 1037, 1039, 1049, 1051, 1061, 1063, 1069, 1073, 1079, 1081,
+ 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1121, 1123, 1129, 1139, 1147,
+ 1151, 1153, 1157, 1159, 1163, 1171, 1181, 1187, 1189, 1193, 1201, 1207,
+ 1213, 1217, 1219, 1223, 1229, 1231, 1237, 1241, 1247, 1249, 1259, 1261,
+ 1271, 1273, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1313,
+ 1319, 1321, 1327, 1333, 1339, 1343, 1349, 1357, 1361, 1363, 1367, 1369,
+ 1373, 1381, 1387, 1391, 1399, 1403, 1409, 1411, 1417, 1423, 1427, 1429,
+ 1433, 1439, 1447, 1451, 1453, 1457, 1459, 1469, 1471, 1481, 1483, 1487,
+ 1489, 1493, 1499, 1501, 1511, 1513, 1517, 1523, 1531, 1537, 1541, 1543,
+ 1549, 1553, 1559, 1567, 1571, 1577, 1579, 1583, 1591, 1597, 1601, 1607,
+ 1609, 1613, 1619, 1621, 1627, 1633, 1637, 1643, 1649, 1651, 1657, 1663,
+ 1667, 1669, 1679, 1681, 1691, 1693, 1697, 1699, 1703, 1709, 1711, 1717,
+ 1721, 1723, 1733, 1739, 1741, 1747, 1751, 1753, 1759, 1763, 1769, 1777,
+ 1781, 1783, 1787, 1789, 1801, 1807, 1811, 1817, 1819, 1823, 1829, 1831,
+ 1843, 1847, 1849, 1853, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1891,
+ 1901, 1907, 1909, 1913, 1919, 1921, 1927, 1931, 1933, 1937, 1943, 1949,
+ 1951, 1957, 1961, 1963, 1973, 1979, 1987, 1993, 1997, 1999, 2003, 2011,
+ 2017, 2021, 2027, 2029, 2033, 2039, 2041, 2047, 2053, 2059, 2063, 2069,
+ 2071, 2077, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2117, 2119, 2129,
+ 2131, 2137, 2141, 2143, 2147, 2153, 2159, 2161, 2171, 2173, 2179, 2183,
+ 2197, 2201, 2203, 2207, 2209, 2213, 2221, 2227, 2231, 2237, 2239, 2243,
+ 2249, 2251, 2257, 2263, 2267, 2269, 2273, 2279, 2281, 2287, 2291, 2293,
+ 2297, 2309, 2311 };
+static int prime_offset_count = 480;
+static int prime_multiplier = 2310;
+static int first_prime_index = 5;
+
+int BN_GENCB_call(BN_GENCB *cb, int a, int b)
+ {
+ /* No callback means continue */
+ if(!cb) return 1;
+ switch(cb->ver)
+ {
+ case 1:
+ /* Deprecated-style callbacks */
+ if(!cb->cb.cb_1)
+ return 1;
+ cb->cb.cb_1(a, b, cb->arg);
+ return 1;
+ case 2:
+ /* New-style callbacks */
+ return cb->cb.cb_2(a, b, cb);
+ default:
+ break;
+ }
+ /* Unrecognised callback type */
+ return 0;
+ }
-BIGNUM *BN_generate_prime(BIGNUM *ret, int bits, int safe, BIGNUM *add,
- BIGNUM *rem, void (*callback)(int,int,void *), void *cb_arg)
+int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe,
+ const BIGNUM *add, const BIGNUM *rem, BN_GENCB *cb)
{
- BIGNUM *rnd=NULL;
- BIGNUM t;
+ BIGNUM *t;
int found=0;
int i,j,c1=0;
BN_CTX *ctx;
- int checks = BN_prime_checks_size(bits);
+ int checks = BN_prime_checks_for_size(bits);
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- if (ret == NULL)
+ if (bits < 2)
{
- if ((rnd=BN_new()) == NULL) goto err;
+ /* There are no prime numbers this small. */
+ BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL);
+ return 0;
}
- else
- rnd=ret;
- BN_init(&t);
+ else if (bits == 2 && safe)
+ {
+ /* The smallest safe prime (7) is three bits. */
+ BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL);
+ return 0;
+ }
+
+ ctx=BN_CTX_new();
+ if (ctx == NULL) goto err;
+ BN_CTX_start(ctx);
+ t = BN_CTX_get(ctx);
+ if(!t) goto err;
loop:
/* make a random number and set the top and bottom bits */
if (add == NULL)
{
- if (!probable_prime(rnd,bits)) goto err;
+ if (!probable_prime(ret,bits)) goto err;
}
else
{
if (safe)
{
- if (!probable_prime_dh_safe(rnd,bits,add,rem,ctx))
+ if (!probable_prime_dh_safe(ret,bits,add,rem,ctx))
goto err;
}
else
{
- if (!probable_prime_dh(rnd,bits,add,rem,ctx))
+ if (!bn_probable_prime_dh(ret,bits,add,rem,ctx))
goto err;
}
}
- /* if (BN_mod_word(rnd,(BN_ULONG)3) == 1) goto loop; */
- if (callback != NULL) callback(0,c1++,cb_arg);
+ /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */
+ if(!BN_GENCB_call(cb, 0, c1++))
+ /* aborted */
+ goto err;
if (!safe)
{
- i=BN_is_prime(rnd,checks,callback,ctx,cb_arg);
+ i=BN_is_prime_fasttest_ex(ret,checks,ctx,0,cb);
if (i == -1) goto err;
if (i == 0) goto loop;
}
* check that (p-1)/2 is prime.
* Since a prime is odd, We just
* need to divide by 2 */
- if (!BN_rshift1(&t,rnd)) goto err;
+ if (!BN_rshift1(t,ret)) goto err;
for (i=0; i<checks; i++)
{
- j=BN_is_prime(rnd,1,callback,ctx,cb_arg);
+ j=BN_is_prime_fasttest_ex(ret,1,ctx,0,cb);
if (j == -1) goto err;
if (j == 0) goto loop;
- j=BN_is_prime(&t,1,callback,ctx,cb_arg);
+ j=BN_is_prime_fasttest_ex(t,1,ctx,0,cb);
if (j == -1) goto err;
if (j == 0) goto loop;
- if (callback != NULL) callback(2,c1-1,cb_arg);
+ if(!BN_GENCB_call(cb, 2, c1-1))
+ goto err;
/* We have a safe prime test pass */
}
}
/* we have a prime :-) */
found = 1;
err:
- if (!found && (ret == NULL) && (rnd != NULL)) BN_free(rnd);
- BN_free(&t);
- if (ctx != NULL) BN_CTX_free(ctx);
- return(found ? rnd : NULL);
+ if (ctx != NULL)
+ {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ bn_check_top(ret);
+ return found;
}
-int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int,int,void *),
- BN_CTX *ctx_passed, void *cb_arg)
+int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, BN_GENCB *cb)
{
- int i,j,c2=0,ret= -1;
- BIGNUM *check;
- BN_CTX *ctx=NULL,*ctx2=NULL;
- BN_MONT_CTX *mont=NULL;
+ return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb);
+ }
+int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
+ int do_trial_division, BN_GENCB *cb)
+ {
+ int i, j, ret = -1;
+ int k;
+ BN_CTX *ctx = NULL;
+ BIGNUM *A1, *A1_odd, *check; /* taken from ctx */
+ BN_MONT_CTX *mont = NULL;
+ const BIGNUM *A = NULL;
+
+ if (BN_cmp(a, BN_value_one()) <= 0)
+ return 0;
+
if (checks == BN_prime_checks)
+ checks = BN_prime_checks_for_size(BN_num_bits(a));
+
+ /* first look for small factors */
+ if (!BN_is_odd(a))
+ /* a is even => a is prime if and only if a == 2 */
+ return BN_is_word(a, 2);
+ if (do_trial_division)
{
- int bits = BN_num_bits(a);
- checks = BN_prime_checks_size(bits);
+ for (i = 1; i < NUMPRIMES; i++)
+ if (BN_mod_word(a, primes[i]) == 0)
+ return 0;
+ if(!BN_GENCB_call(cb, 1, -1))
+ goto err;
}
- if (!BN_is_odd(a))
- return(0);
if (ctx_passed != NULL)
- ctx=ctx_passed;
+ ctx = ctx_passed;
else
- if ((ctx=BN_CTX_new()) == NULL) goto err;
-
- if ((ctx2=BN_CTX_new()) == NULL) goto err;
- if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-
- check= &(ctx->bn[ctx->tos++]);
+ if ((ctx=BN_CTX_new()) == NULL)
+ goto err;
+ BN_CTX_start(ctx);
- /* Setup the montgomery structure */
- if (!BN_MONT_CTX_set(mont,a,ctx2)) goto err;
+ /* A := abs(a) */
+ if (a->neg)
+ {
+ BIGNUM *t;
+ if ((t = BN_CTX_get(ctx)) == NULL) goto err;
+ BN_copy(t, a);
+ t->neg = 0;
+ A = t;
+ }
+ else
+ A = a;
+ A1 = BN_CTX_get(ctx);
+ A1_odd = BN_CTX_get(ctx);
+ check = BN_CTX_get(ctx);
+ if (check == NULL) goto err;
+
+ /* compute A1 := A - 1 */
+ if (!BN_copy(A1, A))
+ goto err;
+ if (!BN_sub_word(A1, 1))
+ goto err;
+ if (BN_is_zero(A1))
+ {
+ ret = 0;
+ goto err;
+ }
- for (i=0; i<checks; i++)
+ /* write A1 as A1_odd * 2^k */
+ k = 1;
+ while (!BN_is_bit_set(A1, k))
+ k++;
+ if (!BN_rshift(A1_odd, A1, k))
+ goto err;
+
+ /* Montgomery setup for computations mod A */
+ mont = BN_MONT_CTX_new();
+ if (mont == NULL)
+ goto err;
+ if (!BN_MONT_CTX_set(mont, A, ctx))
+ goto err;
+
+ for (i = 0; i < checks; i++)
{
- if (!BN_rand(check,BN_num_bits(a)-1,0,0)) goto err;
- j=witness(check,a,ctx,ctx2,mont);
+ if (!BN_pseudo_rand_range(check, A1))
+ goto err;
+ if (!BN_add_word(check, 1))
+ goto err;
+ /* now 1 <= check < A */
+
+ j = witness(check, A, A1, A1_odd, k, ctx, mont);
if (j == -1) goto err;
if (j)
{
ret=0;
goto err;
}
- if (callback != NULL) callback(1,c2++,cb_arg);
+ if(!BN_GENCB_call(cb, 1, i))
+ goto err;
}
ret=1;
err:
- ctx->tos--;
- if ((ctx_passed == NULL) && (ctx != NULL))
- BN_CTX_free(ctx);
- if (ctx2 != NULL)
- BN_CTX_free(ctx2);
- if (mont != NULL) BN_MONT_CTX_free(mont);
-
+ if (ctx != NULL)
+ {
+ BN_CTX_end(ctx);
+ if (ctx_passed == NULL)
+ BN_CTX_free(ctx);
+ }
+ if (mont != NULL)
+ BN_MONT_CTX_free(mont);
+
return(ret);
}
-static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx, BN_CTX *ctx2,
- BN_MONT_CTX *mont)
+int bn_probable_prime_dh_retry(BIGNUM *rnd, int bits, BN_CTX *ctx)
{
- int k,i,ret= -1,good;
- BIGNUM *d,*dd,*tmp,*d1,*d2,*n1;
- BIGNUM *mont_one,*mont_n1,*mont_a;
-
- d1= &(ctx->bn[ctx->tos]);
- d2= &(ctx->bn[ctx->tos+1]);
- n1= &(ctx->bn[ctx->tos+2]);
- ctx->tos+=3;
-
- mont_one= &(ctx2->bn[ctx2->tos]);
- mont_n1= &(ctx2->bn[ctx2->tos+1]);
- mont_a= &(ctx2->bn[ctx2->tos+2]);
- ctx2->tos+=3;
-
- d=d1;
- dd=d2;
- if (!BN_one(d)) goto err;
- if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
- k=BN_num_bits(n1);
-
- if (!BN_to_montgomery(mont_one,BN_value_one(),mont,ctx2)) goto err;
- if (!BN_to_montgomery(mont_n1,n1,mont,ctx2)) goto err;
- if (!BN_to_montgomery(mont_a,a,mont,ctx2)) goto err;
-
- BN_copy(d,mont_one);
- for (i=k-1; i>=0; i--)
- {
- if ( (BN_cmp(d,mont_one) != 0) &&
- (BN_cmp(d,mont_n1) != 0))
- good=1;
- else
- good=0;
+ int i;
+ BIGNUM *t1;
+ int ret = 0;
- BN_mod_mul_montgomery(dd,d,d,mont,ctx2);
+ BN_CTX_start(ctx);
+ if ((t1 = BN_CTX_get(ctx)) == NULL) goto err;
- if (good && (BN_cmp(dd,mont_one) == 0))
- {
- ret=1;
- goto err;
- }
- if (BN_is_bit_set(n1,i))
+loop:
+ if (!BN_rand(rnd, bits, 0, 1)) goto err;
+
+ /* we now have a random number 'rand' to test. */
+
+ for (i = 1; i < NUMPRIMES; i++)
+ {
+ /* check that rnd is a prime */
+ if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1)
{
- BN_mod_mul_montgomery(d,dd,mont_a,mont,ctx2);
+ goto loop;
}
- else
+ }
+ ret=1;
+
+err:
+ BN_CTX_end(ctx);
+ bn_check_top(rnd);
+ return(ret);
+ }
+
+int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, BN_CTX *ctx)
+ {
+ int i;
+ BIGNUM *t1;
+ BIGNUM *offset_index;
+ BIGNUM *offset_count;
+ int ret = 0;
+
+ BN_CTX_start(ctx);
+ if ((t1 = BN_CTX_get(ctx)) == NULL) goto err;
+ if ((offset_index = BN_CTX_get(ctx)) == NULL) goto err;
+ if ((offset_count = BN_CTX_get(ctx)) == NULL) goto err;
+
+ BN_add_word(offset_count, prime_offset_count);
+
+loop:
+ if (!BN_rand(rnd, bits, 0, 1)) goto err;
+ if (!BN_rand_range(offset_index, offset_count)) goto err;
+
+ BN_mul_word(rnd, prime_multiplier);
+ BN_add_word(rnd, prime_offsets[BN_get_word(offset_index)]);
+
+ /* we now have a random number 'rand' to test. */
+
+ /* skip coprimes */
+ for (i = first_prime_index; i < NUMPRIMES; i++)
+ {
+ /* check that rnd is a prime */
+ if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1)
{
- tmp=d;
- d=dd;
- dd=tmp;
+ goto loop;
}
}
- if (BN_cmp(d,mont_one) == 0)
- i=0;
- else i=1;
- ret=i;
+ ret=1;
+
err:
- ctx->tos-=3;
- ctx2->tos-=3;
+ BN_CTX_end(ctx);
+ bn_check_top(rnd);
return(ret);
}
+static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
+ const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont)
+ {
+ if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */
+ return -1;
+ if (BN_is_one(w))
+ return 0; /* probably prime */
+ if (BN_cmp(w, a1) == 0)
+ return 0; /* w == -1 (mod a), 'a' is probably prime */
+ while (--k)
+ {
+ if (!BN_mod_mul(w, w, w, a, ctx)) /* w := w^2 mod a */
+ return -1;
+ if (BN_is_one(w))
+ return 1; /* 'a' is composite, otherwise a previous 'w' would
+ * have been == -1 (mod 'a') */
+ if (BN_cmp(w, a1) == 0)
+ return 0; /* w == -1 (mod a), 'a' is probably prime */
+ }
+ /* If we get here, 'w' is the (a-1)/2-th power of the original 'w',
+ * and it is neither -1 nor +1 -- so 'a' cannot be prime */
+ bn_check_top(w);
+ return 1;
+ }
+
static int probable_prime(BIGNUM *rnd, int bits)
{
int i;
- MS_STATIC BN_ULONG mods[NUMPRIMES];
- BN_ULONG delta,d;
+ prime_t mods[NUMPRIMES];
+ BN_ULONG delta;
+ BN_ULONG maxdelta = BN_MASK2 - primes[NUMPRIMES-1];
+ char is_single_word = bits <= BN_BITS2;
again:
if (!BN_rand(rnd,bits,1,1)) return(0);
- /* we now have a random number 'rand' to test. */
+ /* we now have a random number 'rnd' to test. */
for (i=1; i<NUMPRIMES; i++)
- mods[i]=BN_mod_word(rnd,(BN_ULONG)primes[i]);
+ mods[i]=(prime_t)BN_mod_word(rnd,(BN_ULONG)primes[i]);
+ /* If bits is so small that it fits into a single word then we
+ * additionally don't want to exceed that many bits. */
+ if (is_single_word)
+ {
+ BN_ULONG size_limit = (((BN_ULONG) 1) << bits) - BN_get_word(rnd) - 1;
+ if (size_limit < maxdelta)
+ maxdelta = size_limit;
+ }
delta=0;
- loop: for (i=1; i<NUMPRIMES; i++)
+loop:
+ if (is_single_word)
{
- /* check that rnd is not a prime and also
- * that gcd(rnd-1,primes) == 1 (except for 2) */
- if (((mods[i]+delta)%primes[i]) <= 1)
+ BN_ULONG rnd_word = BN_get_word(rnd);
+
+ /* In the case that the candidate prime is a single word then
+ * we check that:
+ * 1) It's greater than primes[i] because we shouldn't reject
+ * 3 as being a prime number because it's a multiple of
+ * three.
+ * 2) That it's not a multiple of a known prime. We don't
+ * check that rnd-1 is also coprime to all the known
+ * primes because there aren't many small primes where
+ * that's true. */
+ for (i=1; i<NUMPRIMES && primes[i]<rnd_word; i++)
{
- d=delta;
- delta+=2;
- /* perhaps need to check for overflow of
- * delta (but delta can be upto 2^32)
- * 21-May-98 eay - added overflow check */
- if (delta < d) goto again;
- goto loop;
+ if ((mods[i]+delta)%primes[i] == 0)
+ {
+ delta+=2;
+ if (delta > maxdelta) goto again;
+ goto loop;
+ }
+ }
+ }
+ else
+ {
+ for (i=1; i<NUMPRIMES; i++)
+ {
+ /* check that rnd is not a prime and also
+ * that gcd(rnd-1,primes) == 1 (except for 2) */
+ if (((mods[i]+delta)%primes[i]) <= 1)
+ {
+ delta+=2;
+ if (delta > maxdelta) goto again;
+ goto loop;
+ }
}
}
if (!BN_add_word(rnd,delta)) return(0);
+ if (BN_num_bits(rnd) != bits)
+ goto again;
+ bn_check_top(rnd);
return(1);
}
-static int probable_prime_dh(BIGNUM *rnd, int bits, BIGNUM *add, BIGNUM *rem,
- BN_CTX *ctx)
+int bn_probable_prime_dh(BIGNUM *rnd, int bits,
+ const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx)
{
int i,ret=0;
BIGNUM *t1;
- t1= &(ctx->bn[ctx->tos++]);
+ BN_CTX_start(ctx);
+ if ((t1 = BN_CTX_get(ctx)) == NULL) goto err;
if (!BN_rand(rnd,bits,0,1)) goto err;
/* we now have a random number 'rand' to test. */
- loop: for (i=1; i<NUMPRIMES; i++)
+loop:
+ for (i=1; i<NUMPRIMES; i++)
{
/* check that rnd is a prime */
if (BN_mod_word(rnd,(BN_ULONG)primes[i]) <= 1)
}
}
ret=1;
+
err:
- ctx->tos--;
+ BN_CTX_end(ctx);
+ bn_check_top(rnd);
return(ret);
}
-static int probable_prime_dh_safe(BIGNUM *p, int bits, BIGNUM *padd,
- BIGNUM *rem, BN_CTX *ctx)
+static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd,
+ const BIGNUM *rem, BN_CTX *ctx)
{
int i,ret=0;
- BIGNUM *t1,*qadd=NULL,*q=NULL;
+ BIGNUM *t1,*qadd,*q;
bits--;
- t1= &(ctx->bn[ctx->tos++]);
- q= &(ctx->bn[ctx->tos++]);
- qadd= &(ctx->bn[ctx->tos++]);
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ q = BN_CTX_get(ctx);
+ qadd = BN_CTX_get(ctx);
+ if (qadd == NULL) goto err;
if (!BN_rshift1(qadd,padd)) goto err;
if (!BN_lshift1(p,q)) goto err;
if (!BN_add_word(p,1)) goto err;
- loop: for (i=1; i<NUMPRIMES; i++)
+loop:
+ for (i=1; i<NUMPRIMES; i++)
{
/* check that p and q are prime */
/* check that for p and q
* gcd(p-1,primes) == 1 (except for 2) */
- if ( (BN_mod_word(p,(BN_ULONG)primes[i]) == 0) ||
+ if ((BN_mod_word(p,(BN_ULONG)primes[i]) == 0) ||
(BN_mod_word(q,(BN_ULONG)primes[i]) == 0))
{
if (!BN_add(p,p,padd)) goto err;
}
}
ret=1;
-err:
- ctx->tos-=3;
- return(ret);
- }
-
-#if 0
-
-#define RECP_MUL_MOD
-static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx,
- BN_CTX *unused, BN_MONT_CTX *unused2)
- {
- int k,i,ret= -1;
- BIGNUM *d,*dd,*tmp;
- BIGNUM *d1,*d2,*x,*n1;
- BN_RECP_CTX recp;
-
- d1= &(ctx->bn[ctx->tos]);
- d2= &(ctx->bn[ctx->tos+1]);
- x= &(ctx->bn[ctx->tos+2]);
- n1= &(ctx->bn[ctx->tos+3]);
- ctx->tos+=4;
-
- d=d1;
- dd=d2;
- if (!BN_one(d)) goto err;
- if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
- k=BN_num_bits(n1);
-
- /* i=BN_num_bits(n); */
-#ifdef RECP_MUL_MOD
- BN_RECP_CTX_init(&recp);
- if (BN_RECP_CTX_set(&recp,n,ctx) <= 0) goto err;
-#endif
-
- for (i=k-1; i>=0; i--)
- {
- if (BN_copy(x,d) == NULL) goto err;
-#ifndef RECP_MUL_MOD
- if (!BN_mod_mul(dd,d,d,n,ctx)) goto err;
-#else
- if (!BN_mod_mul_reciprocal(dd,d,d,&recp,ctx)) goto err;
-#endif
- if ( BN_is_one(dd) &&
- !BN_is_one(x) &&
- (BN_cmp(x,n1) != 0))
- {
- ret=1;
- goto err;
- }
- if (BN_is_bit_set(n1,i))
- {
-#ifndef RECP_MUL_MOD
- if (!BN_mod_mul(d,dd,a,n,ctx)) goto err;
-#else
- if (!BN_mod_mul_reciprocal(d,dd,a,&recp,ctx)) goto err;
-#endif
- }
- else
- {
- tmp=d;
- d=dd;
- dd=tmp;
- }
- }
- if (BN_is_one(d))
- i=0;
- else i=1;
- ret=i;
err:
- ctx->tos-=4;
-#ifdef RECP_MUL_MOD
- BN_RECP_CTX_free(&recp);
-#endif
+ BN_CTX_end(ctx);
+ bn_check_top(p);
return(ret);
}
-#endif